The present invention relates to a method for placing a virtual machine on a target virtual machine manager out of multiple virtual machine managers, whereby a system management software is connected to the virtual machine managers and selects the target virtual machine manager for placing the virtual machine. The present invention relates further to a method for migrating a virtual machine from a source virtual machine manager to a target virtual machine manager out of multiple virtual machine managers, whereby a system management software is connected to the virtual machine managers and the system management software removing the virtual machine from the source virtual machine manager and placing it on the target virtual machine manager according to the above method. The present invention further relates to a computer readable medium containing a set of instruction that causes a computer to perform one of the above methods and a computer program product comprising a computer usable medium including a computer usable program code, wherein the computer usable program code is adapted to execute one of the above methods.
Virtualization is becoming more and more important in IT architectures and allows the use of central servers for performing different tasks as required by a user. A system for virtualization comprises a computer hardware as known in the art which has a virtual machine manager, also called hypervisor, running thereon. The virtual machine manager can be running directly on the hardware of the computer, which means without an underlying operating system, or as an application with a standard operating system like a Linux, Windows or others. Also virtual machine managers running on an intermediate abstraction layer are known in the art. The virtual machine manager provides an environment for running virtual machines, which are also called guests. These guests are virtual instances of operating systems, which are encapsulated inside the virtual machine manager and can be executed like running directly on a computer hardware.
Depending on the requirements of the users, multiple virtual machine managers can be provided centrally to offer resources for running virtual machines. The virtual machine managers are connected to a system management software, that manages the virtual machine managers, e.g. in respect of the placement of virtual machines. For increased efficiency, the availability of resources like CPU, memory, network load or others are considered in the art for selecting a target virtual manager when a virtual machine has to placed.
Placing of a virtual machine is also important, when migration of a virtual machine from one virtual machine manager to another is required, e.g. to allow maintenance on a virtual machine manager. In this case, the virtual machine on a source virtual machine manager has to be placed on another virtual machine manager connected to the system management software. Migration of a virtual machine can also be important to increase efficiency of the sum of all virtual machine managers connected to the system management software under consideration of available resources.
Frequently, the availability of a computer memory, e.g. a RAM, is one of the most important considerations for the efficiency of the entire system, because a RAM is cost-intensive and thereby limits the number of virtual machines which can be run on a single virtual machine manager.